A vehicle may purposefully enter vehicle drift where the vehicle's driver intentionally oversteers the vehicle and causes the vehicle's rear wheels to slip. The vehicle may negotiate a turn while the vehicle's driver induces the vehicle in the drift maneuver. It may require a driver with a high degree of skill to enter and maintain a vehicle in a drift maneuver. In particular, the vehicle's driver may have to sharply change a steering wheel position while adjusting powertrain torque to induce and maintain wheel slip while maintaining control of the vehicle along a desired travel path. The vehicle's driver may also have to perform other actions to perform the vehicle drift maneuver or maintain vehicle control. For example, the driver may selectively engage and disengage the vehicle's manual parking brake to increase the vehicle slip angle. Thus, a vehicle driver may need to practice and have considerable agility to skillfully enter a vehicle into a drifting maneuver. However, it may be desirable to allow a vehicle driver to enter a vehicle into vehicle drift conditions with less effort for the purposes of teaching and/or closed course exhibition.
The inventors herein have recognized the above-mentioned issues and have developed a vehicle operating method, comprising: receiving a vehicle drift maneuver request via a controller; and opening one or more clutches of a transmission, providing a propulsive torque to a first front wheel of a vehicle, and providing a regenerative braking torque to a second front wheel via the controller in response to the vehicle drift maneuver request.
By adjusting torques applied to a vehicle's front wheels and opening a transmission clutch, it may be possible to provide the technical result of preparing a vehicle to enter a drifting maneuver. In particular, torque of the vehicle's front wheels may be adjusted so that forces applied to the vehicle bring the vehicle closer to a condition where vehicle yaw (e.g., rotation about the vehicle's yaw axis, an axis that extends in a perpendicular direction through the vehicle's center of mass relative to a longitudinal axis of the vehicle) is induced without actually causing yaw. The transmission's clutches are also opened so that engine torque and electric machine torque may be dumped or quickly transferred to vehicle wheels so as to actually create vehicle yaw when a request to generate vehicle lateral acceleration and/or yaw is generated. In this way, the vehicle may be prepared to enter a drift maneuver without the vehicle's driver having to perform complex and/or precisely timed actions.
The present description may provide several advantages. For example, the approach may provide a way of teaching a driver to operate a vehicle in a drift maneuver. Further, the approach may simplify vehicle operation when operating the vehicle in a drift maneuver. Additionally, the approach may ease the vehicle out of the drift maneuver so as to improve vehicle drivability.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.